If the devices are connected to a temperature sensor with a very thin tube, they are so-called capillary temperature regulators, which serve both for signaling and for regulating the temperatures of the monitored medium. They are connected so that the instrument itself is not placed on the pipeline, but due to the considerable length of the flexible capillary, the panel can be positioned to be easily accessible. The sensors are inserted into sensing brass or stainless steel wells, sometimes they are mounted in a rubber grommet in the pipe wall. The length of the capillary and the working range of the regulator can vary considerably for different types; this must be taken into account when planning the installation and purchasing the equipment. Capillary regulators can also be retrofitted, as mounting is not difficult. Depending on the application and use, the controller can be selected for low temperatures (from 0 degrees, for cooling systems with negative values) or vice versa for working with the highest temperature media.